Esters of unsubstituted and alphasubstituted cyclopentenylacetic acid and their production



Patented July 10, 1934 7 1 UNITED? 1,1.965192" i A a ESTERS orUNSUBISTITUTEDAND ALPHA- SUBSTITUTED -OYCLOPENTENYLACETIC Acn) AND THEIRraoncc'rron I Ben -Chaux,fParis, France, ,assignor to Compagnie -DeIBethune, .Bully Les Mines, France, a corporation of France No DrawingifApplication February 26, 1932,. Serial No. 595,428.- In France March 6,1: 3. I

acid and from ix-substitutedRacet-ic acids, the

esters being of the general r mna- .A' I;H c.oo'x' Where denotes acyclopentenyl nucleus, R one atom of hydrogen'or an alkyljcyclopentenylor phcnyl radical; X a radical of alcohol or of 15 ethylene bond in'thec'yelopentenyl nucleusexerts no substantial influence on the fundamentalfragrancy of isomeric esters. The contemplated acids may, therefore,belong either to the seriesAzz I M CH =GH I yon-4311420 ore.

CHPCHQ' R 7 where R ato'm of hydro-geiror alk yl,- cyclopentenyl orphenyl radical, or to the series A1 or to the tautomericcyclopentylidene series: 3

CHz-OHg R orig-H2 R, where R=atom of hydrogen or alkyl, cyclopentenyl orphenyl radical.

= In the prior'art, methods are known, of. pre- 35 paringAz-cyclopentenylacetic acid (1381 513 11 {Eh edition), as vwell asm-cyclopentenylacetic and cyclopentylidenacetic acids (for instance: Wallach, Lieb. Ann. 347, 326 (1906); Harding and I-Iaworth, J. Chem. Soc.97, 486 (1910); Goldberg and Linstead, J. Chem. Soc. (1928), 2344;Linstead, J. Chem. Soc. 1930, 1603).

Methods are also known of preparing a-substituted nz-cyclopentenylaceticacids (for instance: Perkins and Cruz, J. Amer. Chem. Soc;-

49, 517 (1927) Arvin and Adams, J. Amer; Chem.

Soc. 49, 2940 (1927), as well as (at-substituted m-cyclopentenylaceticacids (for instance: K011 and Thakur, J. Chem. Soc. 1930, 2217).

The methods of esterification which may be advantageously used varyaccording to the alcohols brought under reaction.

For instance, in the case of primary or secondary aliphatic or aromaticalcohols, the acid and the alcohol may be heated with return flow in thepresence of a small proportion of a strong phenolI I have found that thepositiorr of the mineral acid, as a catlyz'er, avail being eventuallytaken of the formation of 'azeotropic mixtures for eliminating the waterformed during the reaction. Where a halogen-derivative is inexpensivelyavailable; it may be caused to react on a metallic salt 'of thecontemplated acid.

Where it 'is'a case of esterifying a tertiary al.- cohol or any otheralcohol sensitive to acids and to heat, the chloride or the anhydride ofthe contemplated acid is caused to react cold on the alcohol in thepresence of an organic base.

7 The chloride of the acid may be caused to react on an alcoholic or ona phenolic alkaline derivative.-

"Example Z.'-126 grams of riz-c-yclopentenyb acetic. acid (1 molecule)are heated with return -flow-tog ether with l32 grains ofv isoamylalcohol ("1.5imolecules)'-and'4 grams of pure sulphuric acid at 66Bl-for six hours. The sulphuric acid is then neutralized by means ofsoda, with Congo red as an indicator. Isoamy-l alcohol in excess iseliminated through distillation. Then the residue, after having beenwashed with a sodium carbonate solution, in order to recover the acidwhich hasnot reacted, is rectified under reduced pressure;Az-cyclopentenylacetate of isoamyl boils at116-117C.'U11der 14 mm.

" "By the same methcdesters of Az-cyclopentenylpared: 9 i v Propyl(boiling point -17-mm.= 99 C.) isopropyl (=13. R mm;='-Z673LC.);isobutyl .(B. P. 11 mm.='7 C.); secondary :butyllBLP. 11 mm. -'96-1010.); allyl (BVP. 1-5 mm.=95.96

acetic? acid such as the following may'be pre- Gk); phenylethyl (B. E211 mm.=171 .C.)-; cycloo hexyl' (13. P510 mm-.=132-133 C.) cinnamyl (BLP.'-14 mm.-=201-202 C.).

Example 2.I-n a container provided. with a stirrer is heated, withreturn flow while energetically stirring, a suspension of 148 grams ofAz-cyclopentenylacetate of sodium (1 molecule) finely powdered anddessicated, in 139 grams of benzyl chloride (1.1 molecules). At the endof four hours, most of the acid is esterified. I then treat with waterin order to dissolve the sodium chloride which has been formed and torecover the Az-cyclopentenylacetate of sodium which 1 has not reacted. Ithen rectify the product under reduced pressure after having washed anddried it so as to separate the unaltered benzyl chloride from theAz-cyclopentenylacetate of benzyl. The latter boils at 162163 C. under13 Example 3.I mix little by little, while cooling, 145 grams (1molecule) of chloride of Az-cyclosame method and by means ofhz-cyclopentenylacetic acid: tertiary butyl (B. P. 12 mm.=117" 0.);secondary octyl (B. P. 16 mm.=154-157? 0.); citronellol (B. P. 10mm.:172-173 0.); linalyle (B. P. 6 mm.=108-155 0.); geranyle (B. P. 5mm.=160-161 0.); borneol (B. P. 11 mm.= 164-165" 0.); isoborneol (B. P.13 mm.=171-1'73 0.); guaiacol (B. P. 11 mm.=174-1'76 0.); pcresol (B. P.4 mm.:l47 0.); m-cresol (B. P. 4 mm.:14l 0.); thymol (B. P. 6mm.=159-161 0.); eugenol (B. P. '7 mm.=18'7-190 0.); isoeugenol (B. P.10 mm.=208 0.); carvacrol (B. P. 5 mm.=165-168 0.); menthol (B. P. 12mm.=1'70 0.); vanilline (B. P. 4 mm.=202-203 0.); omethylcyclohexanol(B. P. 8 mm.=137-139 0.); m-methylcyclohexanol (B. P. '8 mm.=138-1400.); p-methylcyclohexanol (B. P. 8 mm.=138- 140 0.), etc.

By means of the chloride of the methyl Az-cyclopentenyl-acetic acid (B.P. 19 mm.=83-84 0.), I can obtain, for instance, esters such as: ethyl(B. P. 3 mm.=68" 0.); isobutyl (B. P. 2 mm.=

' i l-78 0.); benzyl (B. P. 2 mm.=135-136" 0.),

0.); ethyl (B. P. 16 mm.=10l 0.) isobutyl (B. P.

etc.

By means of chloride of the ethyl Azcycl0pentenylacetic acid (B. P. 18mm.=94 0.) I can obtain esters such as: methyl (B. P. 19 mm.=93-95 9mm.=1l l-l15 0.); isoamyl (B. P. 10 mm.=

'122" C.) phenylethyl (B. P. 9 mm.=174-1'75 C.)

etc. I

By means of the chloride of the allyl ha-cyclopentenylacetic acid (B. P.11 mm.=95-98" 0.), I can obtain esters such as: methyl (B. P. 12 mm.=970.); ethyl (B. P. 17 mm.:113-114 0.); propyl (B. P. 14 mm.=124-125 0.);isopropyl (B. P. 16 mm.=116 0.) isobutyl (B. P. 12 mm.= 127-128 0.)isoamyl (B. P. 5 mm.=123-125 0.); allyl (B. P. 15 mm.:124-125 0.);benzyl (B. P. 5 mm.=162-164" 0.); cinnamyl (B. P09 mm.= 207-208 0.),etc.

By means of the bis-A2-cyclopentenylacetic acid (B. P. 13 mm.=-137" 0.),I can obtain esters such as: methyl (B. P. 4 mm.=112-114" 0.); ethyl (B.P. 15 mm.=142-143 0.); isobutyl (B. P. 13 mm.=157-158 0.), phenyl, etc.

By means of the chloride of the phenyl Az-cyclopentenylaoetic acid (B.P. 12 mm.=148 0.), I can obtain such esters as: methyl (B. P. 4-5

mm.=130-131 0.); ethyl (B. P. 4-5 mm.=138-- 139 0.); benzyl (B. P. 3-4mm.:196-197 0.), etc.

Example 4.I add little by little, while energetically stirring, grams ofchloride of Az-CYCIO- pentenylacetic acid (1 molecule) to a suspensionof 116 grams (1 molecule) of dry phenate of sodium having been powderedin 500 cubic centimeters of anhydrous toluene. I then heat the whole ina water bath for four hours while stirring. Then I treat with water and.rectify the washed and dried product. nz-cyclopentenylacetate of phenylboils I at 112-113 0. under 4 mm.

The methods described in the four foregoing examples are applicable toacids of the A1-series and to their cyclopentylidene tautomericderivatives. The esters so obtained have, as to fragrancy, propertiesproximate to those of the corresponding esters of the Az-series.

As examples, the following, esters may be mentioned:m-cyclopentenylacetate of ethyl: B. P.

15-16 mm.- 75-80 0. m-cyclopentenylacetate of .benzyl: B. P. 11-12 mm.=0. Al-cyclopentenylacetate of phenylethyl: B. P. 11-12 mm.=- -1'71" 0.Ai-cyclopentenylacetate of cyclohexyl: B. P. 10 mm.=129-130 0.

I claim as my invention:

1. A process for the preparation of fragrant compositions adapted to beused in the manufacture of perfumes, comprising esterifyingcyclopentenylacetic acid to form compounds represented by the generalformula CH=OH in which R represents an alkyl radical or a phenylradical.

RENE CI-IAUX.

